Field of the Disclosure
The following relates generally to wireless communication, and more specifically to techniques for congestion based roaming in a Wireless Local Area Network (WLAN).
Description of Related Art
Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems are often multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). WLANs are an example of such systems and are widely deployed and used. Other examples of such multiple-access systems may include code-division multiple access (CDMA) systems, time-division multiple access (TDMA) systems, frequency-division multiple access (FDMA) systems, and orthogonal frequency-division multiple access (OFDMA) systems.
A WLAN, such as a Wi-Fi (IEEE 802.11) network, includes one or more access points (APs). The AP simultaneously supports communications for multiple mobile devices or stations (STAs) over a shared radio frequency spectrum. In certain instances, the WLAN implements contention-based protocols that allow multiple devices (e.g., STAs and APs) to share the same wireless medium (e.g., a channel) without pre-coordination and with minimal interference. However, a large number of devices associated with the network (i.e., a more congested network) often leads to an increase in the probability of collisions between device transmissions, thereby reducing the throughput of the network.
An AP and the STAs connected to the AP are referred to as a basic service set (BSS). Oftentimes, the coverage areas associated with multiple BSSs will overlap, and therefore a STA may roam from one BSS to another. In some cases, a STA monitors the received signal strength (RSSI) or signal-to-noise ratio (SNR) of a beacon or packet received from an AP, and if the RSSI or SNR fall below a threshold value, the STA initiates a roaming scan. If the STA identifies a preferred BSS during the roaming scan the STA is handed over from the current BSS to the preferred BSS. This roaming technique, however, tends to favor “sticky” connections with the AP. For instance, the connection data performance (e.g., throughput) of a network can decrease due to factors other than a poor RSSI or SNR. Without observing a drop in the RSSI or the SNR, the STA remains attached to the low-performing network even though APs with better throughput on other channels may be available, resulting in an unnecessary reduction of STA throughput and user experience.